Hajir Pourbabak

Consensus-based distributed control for economic operation of distribution grid with multiple consumers and prosumers

This paper investigates the economic operation of distribution grid with multiple consumers and prosumers using consensus-based distributed control algorithms. Driven by the emerging Smart Grid technologies, a tremendous amount of electricity consumers and prosumers have the potential to actively participate into the retail electricity market. This paper formulates the utility and cost functions of a variety of consumers and prosumers and their local/global constraints. Case studies demonstrate the accuracy, robustness, effectiveness, and scalability of the proposed distributed control approaches for the economic operation of multiple consumers and prosumers under various operating conditions. The distributed control algorithms contained in this paper can apply to many other smart grid applications.

Optimal Routing and Charging of an Electric Vehicle Fleet for High-Efficiency Dynamic Transit Systems

This paper proposes a framework and its mathematical model for optimal routing and charging of an electric vehicle fleet for high-efficiency dynamic transit systems, while taking into account energy efficiency and charging price. Based on an extended pickup and delivery problem, an optimization model is formulated from the transit service providers’ perspective and is applied to an electric vehicle (EV) fleet with economically efficient but small batteries in very urbanized areas. It aims to determine the best route from the origin to the final destination for each EV to satisfy the welfare of all passengers (e.g., travel time and passengers’ travel distance), while maximizing the energy efficiency (e.g., by reducing fuel and charging cost), subject to local/global constraints (e.g., EV charging station availability and battery state-of-charge dynamics). This optimization model is solved as a mixed-integer quadratically constrained programming problem. This paper also explores the potential impact of EV fleet of dynamic commuter transit services on electric distribution systems, such as increased average load.

An Integrated eVoucher Mechanism for Flexible Loads in Real-Time Retail Electricity Market

This paper proposes an innovative economic and engineering coupled framework to encourage typical flexible loads or load aggregators, such as parking lots with high penetration of electric vehicles, to participate directly in the real-time retail electricity market based on an integrated eVoucher program. The integrated eVoucher program entails demand side management, either in the positive or negative direction, following a popular customer-centric design principle. It provides the extra economic benefit to end-users and reduces the risk associated with the wholesale electricity market for electric distribution companies (EDCs), meanwhile improving the potential resilience of the distribution networks with consideration for frequency deviations. When implemented, the eVoucher program allows typical flexible loads, such as electric vehicle parking lots, to adjust their demand and consumption behavior according to financial incentives from an EDC. A distribution system operator (DSO) works as a third party to hasten negotiations between such parking lots and EDCs, as well as the price clearing process. Eventually, both electricity retailers and power system operators will benefit from the active participation of the flexible loads and energy customers.

A game theoretic approach to analyze the dynamic interactions of multiple residential prosumers considering power flow constraints

This paper proposes a game-theoretic approach to study the dynamic interactions between different residential customers with the capability to provide self-generated power in a small-scale residential distribution system, using the DistFlow algorithm to calculate the AC flow. In line with the high penetration of distributed renewable energy, some electric customers can play a more active role in the reconfigurable distribution network. They are not only electricity consumers, but also producers in the future electricity retail market. This paper presents the mechanism for how they can interact with each other under the game-theoretic framework and considers some line constraint conditions with fast effective power flow calculation. It also utilizes a economic directed method to take into account the overload line constraints to improve the economic operation.

A Novel Consensus-based Distributed Algorithm for Economic Dispatch Based on Local Estimation of Power Mismatch

This paper proposes a novel consensus-based distributed control algorithm for solving the economic dispatch (ED) problem of distributed generators (DGs). A legacy central controller can be eliminated in order to avoid a single point of failure, relieve computational burden, maintain data privacy, and support plug-and-play functionalities. The optimal ED is achieved by allowing the iterative coordination of local agents (consumers and DGs). As coordination information, the local estimation of power mismatch is shared among DGs through communication networks and does not contain any private information, ultimately contributing to a fair electricity market. Additionally, the proposed distributed algorithm is particularly designed for easy implementation and configuration of a large number of agents in which the distributed decision making can be implemented in a simple proportional-integral or integral controller. In MATLAB/Simulink simulation, the accuracy of the proposed distributed algorithm is demonstrated in a 29-node system in comparison with the centralized algorithm. Scalability and a fast convergence rate are also demonstrated in a 1400-node case study. Further, the experimental test demonstrates the practical performance of the proposed distributed algorithm using the VOLTTRON platform and a cluster of low-cost credit-card-size single-board PCs.

Control and energy management system in microgrids

As a cutting-edge technology, microgrids feature intelligent EMSs and sophisticated control, which will dramatically change our energy infrastructure. The modern microgrids are a relatively recent development with high potential to bring distributed generation, DES devices, controllable loads, communication infrastructure, and many new technologies into the mainstream. As a more controllable and intelligent entity, a microgrid has more growth potential than ever before. However, there are still many open questions, such as the future business models and economics. What is the cost-benefit to the end-user? How should we systematically evaluate the potential benefits and costs of control and energy management in a microgrid?

Risk-Constrained Optimal Energy Management for Virtual Power Plants Considering Correlated Demand Response

In this paper, we propose a new framework for the optimal virtual power plant (VPP) energy management problem considering correlated demand response (CDR). Our objective is to minimize the VPP operating cost while maintaining the power quality of the system. We formulate a risk-constrained two-stage stochastic program to address uncertainties in day-ahead and real-time electricity prices, renewable energy source’s generation processes, and the CDR relationship. The VPP can also maintain cooling and heating balances by coordinating combined cooling, heating, and power production and CDR units. Extensive simulation results show that the VPP can minimize the operating cost and ensure the energy balance and power quality by coordinating components in the framework we propose.

Robust distributed energy resources management for microgrids in a retail electricity market

In this paper, we propose a framework for robust distributed energy resource (DER) management in microgrids considering a retail electricity market. Our objective is to maximize the total profits of the microgrids while maintaining the reliability and security of the system. We formulate a two-stage robust optimization model to address uncertainties in day-ahead retail electricity price and DERs. Extensive simulation results show that microgrids can maximize the total profit and ensure system reliability and security by coordinating DERs in the framework we propose.

The application of distributed control algorithms using VOLTTRON-based software platform

This paper gives an insight into the applications of an open-source control system platform named VOLTTRON. This platform was developed by the Pacific Northwest National Laboratory. A brief introduction is given on the functionality and key features of the platform. Potential applications in the areas of building control and electric vehicle charging are stated, along with an overview of existing projects. A comparison is also made between VOLTTRON and other related software. An actual implementation case of VOLTTRON is then presented in the case study. The demonstration uses the VOLTTRON platform as a message bus. Decentralized generators and consumers are simulated by 16 single-board computers.

Participation of electric vehicle parking lots into retail electricity market with evoucher mechanism

This paper proposes a framework, named after eVoucher program, to encourage parking lots, with high electric vehicles penetration rate, to participate in the retail electricity market at distribution level. It also entails the demand response, either in the negative (demand decrease) or positive (demand increase) direction, which improves the economic benefits for electric distribution companies and potential resilience in distribution networks. The eVoucher program follows a customer- centric design principle and allows parking lots to coordinate the electric vehicle charging behavior in response to economic incentives from an electric distribution company (EDC). As a third party, distribution system operator (DSO) facilitates the negotiation process between parking lots and EDC. Eventually, the active participation of energy end-users will benefit the retail electricity market and distribution network operators.